CO2 capture, storage, and conversion using a praseodymium-modified Ga2O3 photocatalyst. Issue 36 (5th September 2017) - Huang, Zeai
Abstract : Praseodymium-modified gallium oxide (Pr/Ga2 O3 ) was found to show enhanced activity and selectivity toward CO evolution in the photocatalytic conversion of CO2 using H2 O as an electron donor in an aqueous solution of NaHCO3 as compared to those of bare Ga2 O3 . Abstract : Praseodymium-modified gallium oxide (Pr/Ga2 O3 ) was found to show enhanced activity and selectivity toward CO evolution in the photocatalytic conversion of CO2 using H2 O as an electron donor in an aqueous solution of NaHCO3 as compared to those of bare Ga2 O3 . The as-prepared Pr species, including Pr(OH)3 and Pr2 O2 CO3, on the surface of Ga2 O3 were transformed into Pr hydroxycarbonates (Pr2 (OH)2(3− x ) (CO3 ) x ) and Pr carbonate hydrates (Pr2 (CO3 )3 ·8H2 O) in an aqueous solution of NaHCO3, and then the Pr2 (OH)2(3− x ) (CO3 ) x was further transformed into Pr2 (CO3 )3 ·8H2 O by CO2 bubbling under photoirradiation. This indicates that CO2 molecules dissolved in water can be captured and stored using Pr species in an aqueous solution of NaHCO3 under CO2 bubbling. More importantly, Pr2 (OH)2(3− x ) (CO3 ) x and Pr2 (CO3 )3 ·8H2 O accumulated on the surface were decomposed to CO over the Ga2 O3 photocatalyst with a Ag cocatalyst. Consequently, Ag/Pr/Ga2 O3 exhibits much higher activity (249 μmol h −1 of CO) than the pristine Ag-loaded Ga2 O3 (136 μmol h −1 of CO).